The invention relates to a contact arrangement for a vacuum switch, which includes a stationary contact member and a movable contact member that is arranged opposite the stationary contact member in an axial direction. A coil member is connected to the stationary contact member, and an electrical current that passes through the coil member generates an axially-aligned magnetic field.
With respect to known contact arrangements, German Offenlegungsschrift No. 32 27 482 describes a contact arrangement in a vacuum switch wherein each contact member takes the form of a cup. Slots with equal inclination are milled into the walls of the cup. Each of the contact members have a nonadjacent bottom that is connected to a support element that is a support pin. Opposite the bottom of the contact member, each contact member has contact disk that is slotted substantially in a radial direction, the slots functioning to suppress eddy currents.
Further in accordance with the teachings of Offenlegungsschrift No. 32 27 482, the current flowing through the contact members is deflected by the inclined slots in the walls in such a manner that the current is given a current component flowing in the circumferential direction of the contact members. This current component generates a magnetic field that is in phase with the current and permeates the contact members in the axial direction. When the contacts separate, the axial magnetic field acts to diffuse the arc developing between the contact members. Diffusion of the arc results in reduced burn-off of the contact disks. In addition, the axial magnetic field causes a reduction of arc operating voltage, thereby reducing the power reacted in the arc.
Nevertheless, because the angle of inclination of each of the slots in the walls of the contact members is limited by the external dimensions of the contact members, the axial magnetic field produced by the known contact arrangement is relatively weak.